Previously to a few months ago I had the block IE7 install GPO in place for my network (over 100 XP Pro clients). I unlinked the GPO when I tested IE7 with commonly used websites without any issues.
I am not sure what the percentage of clients received the automatic update & ran through the install wizard of IE7. I have two questions that I haven't found an answer for yet.
1. How can I lookup which clients do not have IE7 installed?
2. How can I force the install of IE7 to the clients who do not have it?